1. Field of the Invention
The present invention pertains to the field of radiation detectors which employ scintillating fibers. More particularly, the present invention pertains to the field of scintillating fiber radiation detectors which are used for homeland security.
2. Description of the Related Art
There is the possibility that radioactive materials, to be used in ‘Dirty Bombs’, can be sent to the U.S. from a foreign location. This can make them a threat to U.S. homeland security. Likely radio-nuclides for terrorist use include Cesium-137 and Cobalt-60 because of their (respective) penetrating radiation quantum energy (0.7 & 1.3 MeV gamma rays), long radiation half-life (30 & 5 years), and known technology for high activity radiation production (e.g., for medical use).
Shortcomings of current baggage, package, container, and portal radiation detection methods are i) the cost of detection equipment, ii) the cost of added personnel and training, iii) the detection delays for baggage, packages and passengers, iv) the possibility that detection can be cheated, and v) the possibility of travel delays or even travel cancellations due to false-positive radiation detection signals.
In addition, there is the possibility of catastrophic radiation exposure in the U.S. homeland, whether due to terrorism, war, nuclear accidents, or other man-made or natural causes. Such exposure may be latent or patent, and requires fast and accurate detection to provide security to those who might otherwise be affected. It would be desirable for responders (or first responders) to a nuclear incident to have a fast-acting, hands-free and eyes-free wearable radiation detector.
The related art is shown in the following documents, each of which is incorporated by reference herein: SAIC Exploranium™ GR-100 brochure; Berkeley Nucleonics Corp. Model 951 nukeALERT Radiation Detector brochure; D-tect Systems Mini-rad-D™ brochure; RAE Systems GammaRAE Pager brochure; RAE Systems NeutronRAE pager brochure; Rad/Comm Systems Corp. web page describing the RC/3A Portable Radiation Detector (http://www.radcommsystems.com/hand.html); Amptek web pages describing the GAMMA-RAD and GAMMA-8000 portable scintillation probe (http://www.amptek.com/grad.html, http://www.amptek.com/gamma8k.html, and http://www.amptek.com/dpp.html); ComTec web pages describing a Low Power Scintillation Probe for (portable) MCA Systems (http://www.fastcomtec.com/fwww/datashee/det/naidet.pdf); Bicron Scintillating Optical Fibers brochure (Saint-Gobain Crystals and Detectors); and McCollough, Kevin P., Radiation Oncology, Biology, Physics Volume 24, Supplement 1, 1992, page 288, which describes a scintillation detector for the calibration of brachytherapy seeds.
U.S. Pat. No. 6,713,765 and corresponding U.S. Patent Application Publication 2003/0168602, both of which are invented by the instant inventor and incorporated by reference herein, reveal a “Scintillating Fiber Radiation Detector for Medical Therapy” that uses a 5 mm cross-section scintillating fiber and a photomultiplier tube attached to a rigid bed for detecting medical radiation.